A new study by a BC-based team of AllerGen researchers demonstrates for the first time that combined exposure to diesel exhaust and an allergen exacerbates the immune response in the bronchial submucosa of allergy-prone individuals.

The study and its findings are described in a new paper in Particle and Fibre Toxicology, for which the lead author is AllerGen HQP Ali Hosseini and the co-authors include AllerGen investigators Drs Chris Carlsten, Jeremy Hirota and Kelly McNagny.

The researchers exposed 12 patients to diesel exhaust and an allergen (or a saline control) in combination on one occasion, and exposed the same subjects to an allergen (or a saline control) and filtered air on another. Bronchial biopsies were performed on the participants 48 hours after each co-exposure. The researchers found that the subjects’ bronchial submucosa contained higher levels of key molecules involved in the initiation of airway inflammation after the diesel-allergen co-exposure, compared to the other exposure combinations.

“Our study design, in contrast to more common single-exposure studies, much better recreated the kind of complex, real-world exposures with which allergic people actually have to contend, ” comments senior author Carlsten. “Given that air pollution poses such a pervasive environmental health risk, we hope that—beyond deepening our understanding of biology—our work will also help to inform those concerned with public health and policy.”

These new findings add to the insights already gained by Dr. Carlsten and his research team in an earlier diesel-allergen co-exposure study, the results of which were published in Thorax.